Crispy Potato Röstis with Red Wine Mushroom Ragù

For the Potato Röstis

• 800 g floury potatoes, peeled
• 1 small onion, grated
• 2 tbsp cornflour
• 1 tsp fine salt
• Black pepper
• 4 tbsp neutral oil

For the Mushroom Ragù

• 600 g chestnut mushrooms, thickly sliced
• 200 g oyster mushrooms, torn
• 2 tbsp olive oil
• 3 shallots, sliced
• 3 garlic cloves, chopped
• 1 tbsp tomato purée
• 200 ml dry vegan-certified red wine
• 250 ml vegetable stock
• 1 tbsp tamari
• 1 tsp Dijon mustard
• 3 sprigs thyme
• 1 tsp balsamic vinegar
• 1 tsp cornflour mixed with 1 tbsp cold water, if needed
• Salt and black pepper

To Serve

• 300 g fine green beans
• 1 tbsp chopped flat-leaf parsley
• Black pepper